Postharvest Preservation of Red Apples Using Edible Coatings and Packaging

Limited comparative evidence exists on how polyamine-based edible coatings, in combination with various packaging systems, simultaneously influence the physical stability and biochemical quality of "Red Delicious" apples during storage. In this study, the effects of edible coatings (spermidine, putrescine, and chitosan) and packaging methods (unpacked, plastic film, and zipper bags) on physical properties (length, thickness, geometric mean diameter, weight, and surface area) and chemical attributes (pH, total soluble solids, total phenolics, flavonoids, and antioxidant activity) were evaluated. ANOVA results indicated that both coatings and packaging significantly influenced apple quality during storage, whereas their interaction effects were generally negligible. Packaging played a more critical role in maintaining dimensional stability, while coatings-particularly spermidine-were more effective at reducing weight loss and geometric alterations. Conversely, coatings significantly preserved phenolic compounds and antioxidant activity, whereas packaging exerted a stronger influence on pH and total soluble solids. Among the packaging treatments, zipper bags demonstrated the best performance in minimizing moisture loss and preserving dimensional integrity. Spermidine coating, on the other hand, showed the greatest efficacy in maintaining both chemical and physical quality attributes. Overall, the combination of spermidine coating and zipper bag packaging is recommended as an efficient and cost-effective postharvest strategy. This approach not only reduces postharvest losses and extends shelf life but also preserves the nutritional and market value of apples, offering substantial economic and export benefits for the horticultural industry. These findings provide actionable guidance for postharvest management and highlight the potential of integrated coating-packaging interventions to reduce losses and enhance value in fruit supply chains.